Forty-seconds was all Conor McGregor needed to best Donald "Cowboy" Cerrone. 

McGregor capitalized on an early shoulder shot to damage Cerrone and then, finish him with a head kick to conclude UFC 246.

It was a shocking result that left Twitter ablaze.

"Welcome back Champ!! @TheNotoriousMMA. πŸ™πŸΎπŸ’ͺ🏾," said Lebron James.

"WOW THAT WAS QUICK" added fellow NBA star Joel Embiid.

"Yes he’s his own man, walks to the beat of his own drummer, but when you see the crowds and suspense that comes with him you have to see the similarities with Floyd Mayweather and Muhammad Ali, great great promoters. @TheNotoriousMMA #UFC246," said Teddy Atlas.

Even Floyd Mayweather had a noteworthy reaction to the fight. The undefeated boxer posted a photoshopped promotional flyer of a rematch between himself and McGregor slated for 2020. 

Dana White commented on the possibility of a Mayweather fight for the UFC: "Listen, we’re doing something with Floyd. We’re doing something with Floyd," White said on Saturday prior to McGregor's fight. "And, umm, you know … I don’t know. It’s like, tonight’s the night of the fight, you got the Khabib fight coming, and there’s just so much going on ... Floyd is in our plans, and we are in Floyd’s plans this year, and we’ll end up doing something."

Check out more Twitter reactions below.